Machine for manufacturing molded pulp articles



Sept 1941- V w. H. RANDALL 2,257,573

MACHINE FOR MANUFACTURING MOLDED PULP ARTICLES Filed Jan. 3, 1938 3 Sheets-Sheet l InVenfor We?! ZerHRan dall W. H. RANDALL MACHINE FOR MANUFACTURING MOLDED PULP ARTICLES Sept. 30, 1941.

3 Sheets-Sheet 2 Filed Jan. 3, 1958 3a Fig.3.

' Inven'for' Walteriifiandall Sept. 1941- w. H. I'Q-QANDALL 2,257,573

MACHINE FOR MANUFACTURING MOLDED PULP ARTICLES- Filed Jan. 3, 1938 3 Sheets-Sheet 3 Inven+or Wdl Z'erH-Ijandall Patented Sept. 30, 1941 UNITED STATES PATENT OFFICE MACHINE FOR MANUFACTURING MOLDED PULP ARTICLES Walter H. Randall, Waterville,

Maine, assignor,

by mesne assignments, to The Canal National Bank of Portland, Portland, Maine, trustee Application Janua y 3, 1938, Serial No. 183,047

8 Claims.

It possesses the advantages of articles which are accurate in shape and ofsuperior finish.

In the preferred embodiment ofmy machine I provide a vertically mounted step by step dry: ing unit carrying a series of equi-distantly spaced. vertically reciprocable holding dies revolving in a fixed orbit series of drying dies corresponding in numberv and a complemental and angular spacing to the holding dies. Each drying die is so mounted that during that period 'of the drying unit cycle in which an article is being transferred to or from its complemental holding die of saidunit, the drying die is orbitally displaced relative to said holding die to permit the coaction of the holding die with dies of other units.

I also provide a horizontally mounted step by step rotating forming unit carrying a plurality of foraminous forming dies adapted to be successively immersed in an aqueous pulp mixture for the suction formation of molded pulp articles thereon. This unit is located in such relation to the orbit of the holding dies of the drying unit that during each complete revolution of the forming die unit each forming die is suecessiveLv stepped into coactive alignment with a holding die for transfer of the wet article to the drying unit.

I also provide a transfer die unit which may carry one or more transfer dies mounted adiacent to and preferably, although not necessarily, on the same shaft as the forming die unit.

The transfer die unit is so arranged that its die or dies are brought into successive coactive alignment with the holding dies of the drying unit at the proper time for the successive transfor of the dried and finished articles from the holding dies to the transfer die or dies. Thereafter the articles are ejected from the machine,

as by means of a blast of fer die or dies.

The transfer of an article from one unit to air through the transanother is accomplished during the period of the stepping cycle in which the units are paused in their rotation with the proper dies in coactive alignment with each other.

All rotating units of the machine may be driven step by step from a common drive, such as a Geneva, which through proper motion transmitting connections drives said units in required synchronism with each other.

The actuation of the various dies as required may be done either mechanically or by air or hydraulically operated mechanisms, or both.

Suitable air and vacuum connections are provided to the various dies as required, and the timing of the air and vacuum to these dies may be properly synchronized, as by means of cam operated valves.

Heat may be applied to the drying unit for distribution to the various dies thereon as required by means of proper connections to the .shaft carrying the drying unit.

An article is first suction formed on a forming die of the forming unit by immersing such die in the liquid pulp mixture. step rotation of the forming unit carries the forming die with its wet article thereon int'o coactive alignment with a holding die of the drying unit. While these two dies are coactively aligned and both units are paused in their rotation, the holding die is coacted with and retracted from the forming die article to itself.

Continued stepping of the drying unit brings a mating drying die, which had previously been orbitally displaced relative to said holding die, into coactive alignment with said holding die and the holding die with its wet article is then coacted with said drying die. These two dies remain in continuous pressure contact during the drying of the article or until the continued step by step rotation of the drying unit brings said dies to a position where it is necessary to retract the holding die with the dried and finished article thereon from the drying die to permit said holding die, in the continued step by step rotation of the drying unit, thereafter to coact first with a transfer die to transfer the dried article thereto and subsequently to coact with a forming die to receive a new article.

After the holding die has retracted from the drying die, carrying with it the dried and tinished article, the drying die is orbitally displaced relative to the holding die to permit successive coaction of the holding die with a transfer die and a forming die in the continued stepping of the drying unit.

Continued step by to transfer the wet The drying die remains so displaced with relation to the, holding die until after a new article has been transferred from the forming die to the holding die and the'drying unit rotated step by step to a position where the holding die may once again coact with the drying. die for the drying and finishing of such new article.

After the dried and finished article is transferred to a transfer die, it is carried by such die to a position where it may be conveniently ejected from the machine, as by means of a blast of air through the transfer die.

In the accompanying drawings I. have illustrated a preferred embodiment of my invention,

together with several modifications suggestive of preferred form of Fig. 1. v

Fig. 4 is a view similar to Fig. 3 showing a modification in which the drying 'dies are piv- -ot-ed and are swung outside the orbit of the holding dies to clear the forming and transfer units. Fig. 5 is a plan view of a machine similar to Fig. 1, except that there are two forming die units for the formation of a multilayer article and an independent transfer die unit for receiving the composite dried articles from the holding dies and ejecting them from the machine, and

I Fig. 6 is a fragmentary elevation showing the transfer unit of the machine of Fig. 5.

Considering the machine of Figs. 1-3 inclusive'. I have indicated at Ill a horizontal intermittently rotated shaft journaled in suitable bearings and supported on the machine frame 'I I. Mounted on shaft I0 is a plurality of equi-distantl spaced foraminous forming dies [2 and a plurality of equi-distantly spaced foramlnous transfer dies".

Pulp stock tank ll mounted on frame II is provided for holding the aqueous stock mixture used for the suction formation of the articles on the forming dies II as they are successively immersed in the pulp stock.

Air and vacuum as required may be supplied to the forming and transfer dies through port box l5. Drainagebetween the port box IE and piping connections to each of the dies.

Geneva '25 which is' mounted on continuously rotating shaft 21. The shaft 11 may be continuously driven by any suitable means such as pulley or gear 21'.

For imparting the required step by step motion to the forming and transfer unit and to insure that his operated in proper mechanical synchronlsm with the drying unit, I provide a suitable motion transmitting connection between the forming and transfer unit and the intermittent drive of the vertical shaft II. This connection may comprise ring gear 28, mounted on vertical shaft l1, pinion 29 and gears 3|! and 3|. If so desired the forming and transfer unit -may be driven by a separate intermittent type of drive and the two drives mechanically or otherwise interlocked so as to insure the required synchronism between the two rotating units.

Air and vacuum connections to the holding dies l9 may be provided as by port box 32 (see' Fig. 3) mounted on hollow shaft l1. Distribution of the air or vacuum to the dies I9 may be by means of pipe or flexible hose as required.

The drying dies 22 are heated and if so desired the holding dies I9 may also be heated. If this heat is to be in the ,formof steam, a swivel steam and condensate connection may be made to the bottom of the shaft lfl with suitable If it is desired to use electric heat, a slip ring unit may be mounted at either top or bottom of shaft II a with suitable connections to each of the dies.

valve arrangement operated outside of the ro-' tating unit or may be accomplished by a suitably operated and timed valve mechanism which may the forming and transfer dies may be by'means of passages 16 in the hubs of said forming and transfer unit (see Fig. 3).

Journaled in and supported by frame II is intermittently rotated vertical shaft II. This shaft may be hollow and at its upper end, car'- riesa spider member ill, the radial arms of which are of equal angular spacement.

Mounted near the free end of each spider arm is a vertically reciprocable foraminous holding die l9. Each holding die is independently reciprocable' as by means of individual hydraulic or air operated cylinders 20 mounted on or forming a part of the spider arms.

- Also mounted on vertical shaft" is a series orfgradial arms 2| .equal in number and angular sriacement and in fixed relation to the arms of tlfe spider l8. On each of these arms 2| is slidably mounted a radially reciprocating die carrier II on which is mounted a. heated drying die 22. cated as required by means of cam roll 24 mounted on carrier 2| and engaged in the race- Each die carrier 2| is radially reciprobe mounted on the rotating unit carried by vertical shaft ll. While I have shown the holding dies to be operated by hydraulic or air cylinders, it should be understood that I do not limit myself to this method of operation and that it is feasible to provide. a mechanical arrangement which would impart the required timed motion to each of the holding dies.

The operation of this machine Each forming die of the forming unit is successivelyv revolved through the aqueous stock mixture-in the pulp tank II and during the time it is immersed in this pulp mixture an article is suction-formed thereon. Continued rotation of.

article is transferred to it.

Previous to this period of transfer of the wet article from the forming die to the holding die, the mating dryin die 22 had been radially retracted within the orbitot the holding die (see is as follows.

rm. 1-) so as to clear the rel-mm; die unit permit the coaction between the forming die and the holding die. I

After the holding die has received the wet article from the forming die, continued rotation of the machine camsthe drying die into pro- Jected position which brings it into coactive alignment withits mating holding die. As soon as this coactlve alignment is accomplished, the

holding die with itswet'article closes on its mating drying die and stays closed on said die under sustained pressure contact during subsequent rotation of the drying unit and until these dies have revolved to a point adjacent the transfer die unit where the holding die with its now dried article is retracted i'romthe drying die.

Continued rotation oi the drying unit beyond this point cams said drying die inside the orbit of the holding die (see Fig. 1) for clearance between the drying die and the transfer die unit and brings the holding die in paused coactive alignment with a transfer die. The holding die is then coacted with th transfer die and air under pressure is applied through the holding die and'suction to the transfer die. The holding die is then retracted leaving the dried andfinished article on the transfer die for subsequent ejection from the machine by means of a blast of air through th transfer die. This completes the cycle for the manufacture of one article; The cycle is then repeated and is the same for each successive set of complemental dies.

It is obvious that for each complete revolution of the drying unit there are as many articles successively formed,'successively transferred in the holding dies. and successively dried and finished and ejected from. the machine as there are complemental pairs of holding and drying dies on the drying unit.

Fig. 4 shows in vertical section a modification of the machine of Figs. 1-3. The difference between this machine and the machine previously described lies entirely in the method of mounting the drying dies and successively moving these dies outside th orbit of th holding dies to clear the forming and transfer die unit and tion of the holding dies with the forming and transfer dies of this unit.

During that part of the rotating cycle of the drying unit in which each mating pair 01 holding and drying dies is revolving outside the zone of the forming and transfer die unit, the drying dies are successively swung into coactive alignment with their respective holding dies and the holding dies with their wet articles are successively coacted with and remain continuously in pressure contact with their complemental drying dies.

As each mating pair of holding and drying dies is stepped into proximity to the transfer die unit, the holding die retracts, retaining its dried and finished article. Continued stepping of the drying unit swings the complemental drying die outside the orbit of the holding dies for clearance with the transfer unit and brings the holding die into paused coactive alignment with a transfer die for transfer'of the dried and finished article to such transfer die for subsequent ejection from the machine.

7 The machine of Fig. 4 otherwise operates the same as the machine of Figs. 1-3.

The machine or Figs. 5 and 61s designed for the formation of multilayer articles. It diflers fromthe machines previously described in that die oscillating type, operated by means of air or hydraulic cylinder as at 42. The transfer die 43 is pivoted to the frame as at N and connected to operating cylinder H by any suitable linkage.

, It is swung to the vertical position as shown for to permit successive coactiou of the holding dies with the dies of the forming and transfer unit for purposes of article transfer.

On the machine of Fig. 4 the drying dies 22 are mounted on individual swinging carriers II which are pivoted to the several arms of the spider member II as at ll.

For imparting the required swinging motion to each carrier 33 and drying die 22 a fixed .cam 38 is mounted on the machine frame ii. Connection between fixed cam 8i and each of the swinging carriers II is by means of individual cam rolls 31 ngaged in the cam raceway and mounted on the individual slide blocks 1' which are slidably mounted on the arms of the spider ll. Connecting link it connects each slidabiy mounted block ll to a carrier 33.

The shape of the raceway of fixed cam 38 is such as to impart the required -swinging motion to each carrier 33 and its drying die 22 so that duringthat part of the rotation of the drying unit in which the holding dies I! are in coactive alignment with either the transfer dies or the forming dies, their mating drying dies and carriers are swung outside the orbit of the holding dies for clearance with the forming and transfer die unit to permit the successive coacsuccessively receiving the dried multi-layer articles from the holding dies and successively swung to the horizontal position shown dotted in Fig. 6 for ejecting each article from the die and machin as by means of ablast of air.

The cycle of operation of the machine of Figs. 5 and 6 differs from the machines previously described only in that each holding die first coacts with a forming die of the forming die unit II and removes the article layer from it and then steps into coactive alignment with a forming die of the second forming die unit l2 so that the article layer from the second forming die is superimposed on the article layer removed from the first forming die. Except for the addition of the second forming die unit and the diil'erence in the type of transfer die unit, the operation of the machine is the same as described for the machines of Figs. 1-4.

In the machines of Figs. 1-4 inclusive, I have shown the forming and transfer dies as mounted on a common shaft. It is obvious, however, that the forming die' unit, and the transfer die unit may be mounted on separate shafts having diiferent axes ofrotation.

Also, if desired, a swinging transfer die unit such as shown in Figs. 5 and 8 may be substituted for th intermittently rotating type of tran'sfer die unit shown in Figs. 1-4.

Similarly if desired the machines of Figs. 5 and 6 may be provided with more than two forming units for the formation of articles of three or more layers.

In all of the machines shown the number of production and physical characteristics wanted n the finished product. Obviously, there is considerable possible variatlon inthe arrangement and operation of the various; dies of the various units to permit the transfer of the articles to and from one unit to the other. For instance, the holding dies may be non-reciprocable and the diesel the forming and transfer units may be reciprocable as well as intennittently revoluble for the transfer of articles to and from these units and the drying dies may be vertically reciprocable as well as orbitally displaceable or the holding dies may be orbltally displaceable for transfer of the articles from the forming dies and to the transfer dies.

, and angular spacing to said holding dies, means for rotating said shaft step by step, means for placing wet formed articles on said holdingv dies,

- means for coacting each holding die, witha wet article thereon, with its 'complemental drying die during a substantial portion of the rotating cycle of said shaft to dry the article between said pair of dies under heat and mechanical pressure, means for discharging the dried articles from said holding dies at the completion of the drying cycle,

and means for displacing each drying die from the ,path of coactive movement of its complemental holding die during those portions of the rotating cycle of said shaft at which a wet formed article is being placed on each holding die and at which each holding die is discharging a dried article.

2. A fibrous pulp molding machine comprising a rotary step by step forming and transfer die shaft carrying a series of foraminous forming dies for the suction formation of wet molded pulp articles, an intermittently rotating drying shaft naving its axis of rotation disposed substantially at right angles to the axis of rotation of said first named shaft and carrying a series of spaced holding dies and a complemental series of drying dies corresponding in number and angular spacing to the holding dies, a series of foraminous transfer dies on the forming and drying units may be varied as desiredto give the required machine are paused in their revolution for transferring the dried article from the holding die to'the transfer die, and means for displacing each drying die from the path of coactive movement of its complemental holding die during the periods in which the holding die is removing a wet article from a forming die and is transferring a dried article to a transfer die. 3. A machine for manufacturing multilaye molded fibrous pulparticles, comprising a rotary step by step forming shaft carrying at least two adjacent'series. of foraminous forming dies for the suction formation of wet molded pulp article layers, an, intermittently rotating drying shaft carrying a plurality of spaced holding dies and a plurality of drying diescorresponding in number and angular spacing to the holding dies, means for rotating said shafts step by step in synchronism to bring the forming dies into coactive alignment with the holding dies for the successive transfer of article layersto the holding dies, means for successively imparting coactive movements to each holding die first to coact said holding die with a forming die of each of said series of forming dies while said dies are paused in their revolution for successively transferring wet article layers in superimposed order to the holding die and then to coact said holding die with its complemental drying die for drying the composite article under continuous heat, pressure dies carried by said forming and transfer die shaft for receiving and ejecting dried articles from the machine, means for rotating said shafts step by step in synchronism to bring the forming dies and the transfer dies int coactive alignment with the holding dies for the successive transfer of wet articles from said forming dies to said holding dies and dried articles from said holding dies to said transfer dies, means for successively imparting ccactive movements to'each holding die first t coact said holding die with a forming die while said dies are paused in their for a substantial portion of the rotating cycle of and vacuum for a substantial portion of the rotating cycle of said drying shaft between said holding die and said drying die and subsequently for discharging the dried composite article from said holding die, and means for displacing each drying die from the path of coactive movement of its complementai holding die during the periods in I which the holding die is successively removin wet article layers from the forming dies and a composite dried article is being discharged from themachine.

4. A fibrous pulp molding machine comprising a rotary step by step forming shaft, a foraminous forming die for the suction formation of a wet molded pulp article mounted on and revoluble with said shaft, a rotary step by step drying shaft mounted adjacent to but independently of said forming shaft, a foraminous holding die and a coacting drying die both of which are mounted on and revoluble with said drying shaft, said holding die being reciprocably mounted relative to said drying die and said drying die being of complemental size and shape to said holding die and being displaceable relative to the path of reciprocation of said holding die, means for rotating both of said shafts step by step in synchronism with each other to bring the forming die and the holding die into positions of coactive alinemcnt with each other, means operative while both of said shafts are paused in their rotation for successively imparting reciprocating movesaid drying shaft and subsequently to coact said holding die .with'a transfer die while said diesin which the holding die is removing a wet article from the forming die and is discharging a dried article.

5. The machine of claim 4, in which the means for subsequently dischar ing the dried article from the holding die comprises a transfer die pivotally mounted relative to the holding die to receive the dried article from the holding die. and means for swinging said transfer die to a position for ejecting the dried article from the machine. g

6. A fibrous pulp molding machine comprising a rotary step by step forming shaft, a foraminous forming die for the suction formation of a wet molded pulp article mounted on and revoluble with said shaft, a rotary step by step drying shai't mounted adjacent to but independently of said forming shaft, a foraminous holding die and a coacting drying die both of which are mounted on and revoluble with said drying shaft, said holding diebeing reciprocably mounted relative to said drying die and said drying die being of complemental size and shape to said holding die and being displaceable relative to the path of' reciprocation of said holding die, a transfer die mounted on and revolving with said forming shaft for receiving a dried article from the holding die and ejecting it from the machine, means for rotating both of said shafts step by step in synchronism with each other to bring the forming die and the 'holding die into positions of coactive alinement, with each other. means operative while both of said shafts are paused in their rotation for successively imparting reciprocating movements to said holding die first to cause said holding die to coact'with said forming die to thereby transfer a wet article to the holding die, thereafter to cause said holding die, with the wet article thereon, to coact with said drying die to thereby dry the article between said pair of dies under heat and mechanical pressure, and finally to cause said holding die to coact with the transfer die to transfer the dried article from the holding die to the transfer die for ejection from the machine, and means for displacing the drying die from the path of reciprocating movement of the holding die during' the periods in which the holding die is'removinga wet article from the forming die and is roll, and a fixed cam with which said cam roll coacts. a

WALTER H. RANDALL. 

